Deflection yoke mounting structure



Oct. 1, 1968 J, w, M LEOD, JR.. ETAL 3,404,228

' v DEFLECTION YOKE MOUNTING STRUCTURE Filed March 28, 1966 2 SheetsSheet l INVENT Jam: 1% 1147500, Ill/:4 Me flu 1968 J. w. MCLEOD, JR, ETAL 3, 04,228

DEFLECTION YOKE MOUNTING STRUCTURE Filed March 28, 1966 2 Sheets-Sheet 2 INVENTORS Jamil/M! J MIN/401814205171);

United States Patent 3,404,228 DEFLECTION YOKE MOUNTING STRUCTURE James W. McLeod, Jr., Indianapolis, and William R. Abraham, New Whiteland, Ind., assignors to Radio Corporation of America, a corporation of Delaware Filed Mar. 28, 1966, Ser. No. 538,074 9 Claims. (Cl. 17s-7.s)

This invention relates to apparatus for mounting an electron beam deflection yoke relative to a cathode ray device.

The present day trend in cathode ray picture tubes for television receivers and the like is toward shorter tubes and greater beam deflection angles. With shorter tube necks, it is necessary to mount such adjuncts as deflection yokes, centering devices etc., by means which take a minimum of space. Such a requirement is particularly necessary with color picture tubes of the shadow mask variety, for example. These tubes require additional apparatus such as a convergence magnet yoke and lateral magnets to be mounted on the tube neck.

It is an object of this invention to provide a mounting structure for a deflection yoke which is economical of space, light in weight, easily installed and susceptible of easy yoke position adjustment.

In accordance with the invention, the main yoke support comprises a discontinuous annular collar having feet forwardly extending therefrom, an arcuate bridging member at least partially spanning the gap in the discontinuous collar, and means for ladjustably fastening the bridging member to the collar so as to securely grip the forward end'of the deflection yoke.

The yoke mounting structure also includes a protective cap for the rear end of the yoke and the terminal plate therefor. The cap is a shallow cup-shaped device having a centrally apertured, circular planar end Wall from the periphery of which there is a forwardly extending skirt. The cap has fingers internally thereof for engagement with the yoke terminal plate. A centering ring having a central opening provided with means for encircling and gripping the neck of the picture adjustably attached to the end wall of the protective cap.

For a better understanding of the invention, reference may be made to the following description which is given in conjunction with the following drawings of which:

FIGURE 1 is a side view of the yoke mounting structure in relation to a picture tube supported in a cabinet;

FIGURE 2 is a sectional view taken on the line 2-2 of FIGURE 1 and generally showing the rear end of the yoke mounting structure;

FIGURE 3 is a fragmentary perspective view (somewhat enlarged) of the adjustment features of the mounting structure;

FIGURE 4 is a sectional view (somewhat enlarged) taken on the line 4-4 of FIGURE 2 and showing details of one of the adjustment features; and- PIGURE 5 is a fragmentary view of the inside of the protective cap showing its attachment to the terminal plate of the yoke.

In FIGURE 1 there is shown a cathode ray picture tube 11 having a flared forward section 12 in which there is housed a viewing screen (not shown) on the inside of the face plate 13. The picture tube also has a neck 14 which connects with the flared forward section 12 and extends rearwardly and in which there is housed the electron gun structure (not shown). The picture tube 11 is mounted in a cabinet in which only the front panel 3,404,228 Patented Oct. 1, 1968 "Ice 15 is indicated. The tube mounting is achieved by means such as a plurality of brackets 16 attached to the front panel 15, in conjunction with a metallic band or heavy wire 17 encircling the flared front section of the picture tube substantially as shown.

The deflection yoke which is to be mounted by means of the structure embodying the present invention, is indicated by some of the broken lines in FIGURE 1. The front end 18 of the yoke is conventionally circular as is also the rear end 19. The yoke also has a terminal plate 2-1 adjacent the rear end 19. This plate is provided with a plurality of notches spaced about the periphery thereof (see FIGURE 5).

One part of the yoke mounting structure embodying this invention comprises an annular collar 23 having a plurality of feet 24 angularly extending forwardly therefrom. Each of these feet is provided with means such as a stud 25 for the attachment of one end of a spiral spring 26, the other end of which is attached to one of the brackets 16. By means of such an arrangement, the feet 24 of the collar 23 are urged into firm contact with the flared forward section 12 of the picture tube 11. The front end 18 of the deflection yoke is held in position by the collar 23 which is provided with an adjustment feature 27 to be described in detail subsequently.

Another part of the yoke mounting structure is a shallow cup-shaped member 28 having a circular planar end wall 29 from the periphery of which there is forward- 1y extending skirt 31. This structure serves protect the rear end 19 of the yoke and the terminal plate 21 therefor. A centering ring 32 is adjustably attached to the end wall 29 of the protective cap 28 by means such as a plurality of screws 33 and cooperating speed nuts (not shown). This centering ring is provided with a plurality of inwardly extending fingers 34 which are adapted to grip the neck 14 of the picture tube 11. Also, the holes in the ring 32 preferably are somewhat larger than required to pass the screws 33 in order to enable an adjustment later to be described.

The adjustment means 27 and other features of the collar 23 of FIGURE 1 are shown in greater detail in FIGURES 2, 3 and 4. The discontinuous collar 23 is provided with an outwardly extending shelf 35 adjacent one end 36 of the collar and an outwardly extending ledge 37 adjacent the other end 38 of the collar. As shown more clearly in FIGURE 4, a stud 39 is anchored in the ledge 37. One surface of the shelf 35 is provided with a series of serrations 41. The adjusting means 27 also includes an arcuate bridging member 42 having a curved wall 43 which effectively bridges a major portion of the gap between the ends 36 and 38 of the collar 23. As shown in FIGURE 3, one surface of the bridging member 32 is provided with a series of serrations 44. The bridging member 42 is adjustably positioned on the shelf 35 by suitably engaging the serrations of these two components and is secured to the shelf 35 by means of a screw 45 extending through a slot 46 of the bridging member 42 into a tapped hole 47 in the shelf 35. As an alternative coming within the purview of the invention, the described adjustable attachment of the bridging member 42 to the shelf 35 may be omitted and these two components may be permanently attached to one another.

The bridging member 42 is secured to the ledge 37 by means of a nut 48 threaded onto the stud 39 through a conically shaped hole 49 in the bridging member. The

nut has a conically tapering extension 51 for cooperative engagement with the hole 49 of the bridging member 42.

The installation of the deflection yoke in the described mounting structure is substantially as follows. The forward end of the yoke is inserted in the annular collar 23 until the front end 18 rests against a shoulder 52 (FIGURE 3) extending around the inside of the collar. With the nut 48 and its tapering extension 51 loosely engaged with the conical hole 49 in the bridging member 42, this member is moved relative to the shelf 35 so as to effect an approximate initial engagement of the collar 23 with the front end of the yoke. The screw 45 is tightened to securely anchor the bridging member 42 relative to the shelf 35 and the end 36 of the collar 23. The nut 48 is then tightened on the stud 39 so that, by means of its tapered extension 51, it effectively earns the bridging member 42 into a position whereby the front end 18 of the deflection yoke is securely clamped by the collar 23, supplemented by the arcuate wall 43 of the bridging member 42.

The movement of the bridging member 42 relative to the ledge 37 may be facilitated by means of a V-shaped rail 53 (FIGURE 2) formed on the surface of the ledge. IA. corresponding V-shaped groove (not shown) formed in the surface of the bridging member 42 cooperates with the rail 53 to guide the movement of the bridging member. Also, the engagement of the feet 24 with the flared section of the picture tube may be enhanced by provid ing adhesive or friction pads 54 on the surfaces of the feet which engage the picture tube.

The protective cap 28 is provided internally thereof, with a plurality of fingers 55 which respectively engage corresponding notches 56 in the periphery of the terminal plate 21 as illustrated in FIGURE 5. The screws 33, may be loosened so that the centering ring 32 may be adjusted relative to the end wall 29 of the cap 28 in order to properly locate the rear end 19 of the deflection yoke relative to the neck 14 of the picture tube 11. Finally, the screws 33 are tightened so as to maintain the selected location of the yoke relative to the picture tube neck. The described adjustment may be made so as to slightly elevate the rear end '19 of the yoke if desired. Such an adjustment has been found desirable in mounting defleciton yokes, particularly those used with shadow mask type color picture tubes.

Following such adjustment the nut 48 of the adjusting apparatus 27 may again be loosened, thereby releasing the engagement of the collar 23 with the forward end 18 of the deflection yoke. The yoke and the protective cap 28 with its atached centering ring 32, may then be moved toward the rear of the picture tube if necessary in order to place the yoke in the proper position to effect optimum color purity in the picture tube. Such adjustment is made possible because the plurality of bifurcated fingers 34, even though they grip the neck 14 of the tube tfirmly, still may be slid longitudinally of the tube neck without disturbing the axial position of the rear end of the yoke relative to the picture tube neck. Finally, the nut 48 is again tightened to secure the yoke in such an adjusted position, thereby completing the yoke mounting.

What is claimed is:

1. An assembly for mounting an electron beam deflection yoke, having a circular front end and a peripherally notched terminal plate adjacent its rear end, relative to a picture tube, having a flared forward section sousing a viewing screen and a rearwardly extending connecting neck section housing electron gun structure, said mounting assembly comprising:

a discontinuous annular collar having an inside diameter substantially equal to the outside diameter of the circular front end of said yoke and a plurality of forwardly extending feet;

an arcuate bridging member substantially spanning the two ends of said discontinuous annular collar and 4 having at least a first end movable relative to said collar;

first means for adjustably attaching said movable first end of said arcuate bridging member to said annular collar adjacent to one end thereof to effect a secure gripping of the circular front end of said yoke by said collar; and

means attached to said feet for urging said mounting assembly and said yoke forwardly to press said feet firmly against the flared forward section of said picture tube.

2. A deflection yoke mounting assembly as defined in claim 1 and additionally including:

an enclosure for the rear end of said yoke having means for centering said yoke about the neck of said picture tube.

3. A deflection yoke mounting assembly as defined in claim 1 wherein said first adjustable attaching means comprises! means having a cam surface formed in said arcuate bridging member adjacent said movable first end thereof; and

fastening means having a camming surface cooperating with the cam surface of said bridging member to draw said annular collar into secure gripping contact with the circular front end of said yoke by a tightening of said fastening means.

4. A deflection yoke mounting assembly as defined in claim 3 wherein said first adjustable attaching means comprises:

a ledge extending from the outer surface of said annular collar adjacent to said one end thereof and having a threaded stud projecting from one surface thereof;

said cam surface formed in said arcuate bridging member being a tapered hole extending therethrough to receive said stud; and

said fastening means being a nut having a conically tapering extension for engagement respectively with said stud and said tapered hole through said arcuate bridging member.

5. A deflection yoke mounting assembly as defined in claim 4 and additionally comprising:

a shelf extending from the outer surface of said annular collar adjacent to the other end thereof and having serrations on one surface thereof;

said arcuate bridging member having a second end movable relative to said collar and provided with serrations on one surface of said movable second end; and

means including the mutual engagement of said two sets of serrations for fastening said second end of said arcuate bridging member to said shelf of said annular collar in a selected position.

6. A deflection yoke mounting assembly as defined in claim 5 and additionally including:

a protective cap for said yoke comprising a centrally apertured substantially circular planar end wall and an annular skirt extending around said end wall;

means for attaching said cap to said yoke terminal plate so that said annular skirt encloses said terminal plate;

a centering device having an inner opening provided with means :for encircling and gripping the neck of said picture tube; and

means for attaching said centering device to said protective cap with the device opening and the cap aperture in substantial alignment.

7. A deflection yoke mounting assembly as defined in claim 6 wherein:

said protective cap has a plurality of resilient fingers extending from said planar end wall inside of said annular skirt and adapted to engage the peripheral notches of said yoke terminal plate.

5 6 8. A deflection yoke mounting assembly as defined in References Cited claim 7 wherein: UNITED A P T said centering device has a plurality of bifurcated fin- TES ATEN S gers extending inwardly of said opening and adapted 21484345 10/1949 Hmz 178 7'8 to firmly engage the neck of said picture tube. 5 2900630 8/1959 summrer 178 7'8 9. A deflection yoke mounting assembly as defined in 3356879 12/1967 Renmck 335.210 claim 8 wherein: said attaching means for said centering device is of a ROBERT GRIFFIN Primal) Examme' character to enable adjustable positioning of the open- R. ECKERT, JR., Assistant Examiner.

ing therein relative to the aperture of said protective 10 cap. 

1. AN ASSEMBLY FOR MOUNTING AN ELECTRON BEAM DEFLECTION YOKE, HAVING A CIRCULAR FRONT END AND A PERIPHERALLY NOTCHED TERMINAL PLATE ADJACENT ITS REAR END, RELATIVE TO A PICTURE TUBE, HAVING A FLARED FORWARD SECTION SOUSING A VIEWING SCREEN AND A REARWARDLY EXTENDING CONNECTING NECK SECTION HOUSING ELECTRON GUN STRUCTURE, SAID MOUNTING ASSEMBLY COMPRISING: A DISCONTINUOUS ANNULAR COLLAR HAVING AN INSIDE DIAMETER SUBSTANTIALLY EQUAL TO THE OUTSIDE DIAMETER OF THE CIRCULAR FRONT END OF SAID YOKE AND A PLURALITY OF FORWARDLY EXTENDING FEET; AN ARCUATE BRIDGING MEMBER SUBSTANTIALLY SPANNING THE TWO ENDS OF SAID DISCONTINUOUS ANNULAR COLLAR AND HAVING AT LEAST A FIRST END MOVABLE RELATIVE TO SAID COLLAR; FIRST MEANS FOR ADJUSTABLY ATTACHING SAID MOVABLE FIRST END OF SAID ARCUATE BRIDGING MEMBER TO SAID ANNULAR COLLAR ADJACENT TO ONE END THEREOF TO EFFECT A SECURE GRIPPING OF THE CIRCULAR FRONT END OF SAID YOKE BY SAID COLLAR; AND MEANS ATTACHED TO SAID FEET FOR URGING SAID MOUNTING ASSEMBLY AND SAID YOKE FORWARDLY TO PRESS SAID FEET FIRMLY AGAINST THE FLARED FORWARD SECTION OF SAID PICTURE TUBE. 